books.google.comhttp://books.google.com/books/about/The_Elements_of_Euclid_viz_the_first_six.html?id=KAJ8g5zuFdoC&q=proportionals&utm_source=gb-gplus-shareThe Elements of Euclid; viz. the first six books, together with the eleventh and twelfth. Also the book of Euclid's Data. By R. Simson. To which is added, A treatise on the construction of the trigonometrical canon [by J. Christison] and A concise account of logarithms [by A. Robertson].